High and low water alarm for steam-boilers.



C. E. ROBISON.

HIGH AND LOW WATER ALARM FOR STEAM BOILERS.

APPLICATION FILED FEB. 16. 1911.

1,045,892 4 Patented D0113, 1912.

2 SHEETS-SHEET l.

g w k C. E. ROBISON.

HIGEAND LOW WATER ALARM FOR STEAM BOILERS.

APPLICATION FILED IEBJG, 1911.

1,045,892. Patented Dec. 3, 1912.

2 SHEETS-SHEET 2.

COLUMBIA ELANOGR-APH COHWASHINGTOE, D. C

UNITED STATES PATENT OFFICE.

CHARLES EVARD ROBISON, OF HARRISBURG, PENNSYLVANIA.

HIGH AND LOW WATER ALARM FOR STEAM-BOILERS.

To all whom it may concern:

Be it known that 1, CHARLES E. RoBIsoN, a citizen of the United States,and resident of Harrisburg, Dauphin county, State of Pennsylvania, haveinvented certain new and useful Improvements in High and Low lVaterAlarms for Steam-Boilers, of which the following is a specification.

This invention relates to improvements in the class of signals or alarmswhich are employed for indicating certain water levels in liquid holdingreservoirs.

The invention is intended for use with all classes of liquid holdingreservoirs but is practically adapted for use with steam boilers and oneof its objects is the provision of a circuit closer in the form of afloat actuated by the water in the boiler to open and close an electriccircuit and which is constructed to withstand the maximum steam pressurethat may be generated in the boiler to which it is applied withoutdecreasing the buoyant properties or the mass thereof.

' Another object resides in the employment of a plurality of contactmembers and the arrangement of the same at the opposite end portions ofthe water space of the boiler of a locomotive or other traction devicefor the purpose of indicating to the attendant the height of the watercolumn at either end of the boiler, so that when the engine is going upor down grade an alarm will be sounded if the surface of the water atthe higher end of the boiler is below a certain point, whereupon theattendant will cause more water to run into the boiler and thus thedanger of overheating the crown sheets and consequent explosion will beprevented.

These and other objects will appear and be better understood from thefollowing description taken in connection with the accompanyingdrawings, in which,

Flgure l is a diagrammatic view of the apparatus applied to the oppositeend portions of the water chamber of a boiler; Fig. 2 is a detaillongitudinal section taken through the water chamber of a tractionboiler showing the device in side elevation; Fig. 3 is a detail end viewof the device partly in section also showing one side of the boiler invertical section; Figs. 4: and 5 are a plan and a side elevationrespectively of a locomotive boiler showing the water chamber and thecrown sheet in dotted lines and my device in operative position.

The boiler has the usual tube space 1, fire Specification of LettersPatent.

Application filed February 16, 1911.

Patented Dec. 3, 1912.

Serial No. 608,959.

box 2, water chamber 3 and crown sheet 1 which divides the fire box 2and water chamber 3. The sides of the water chamber are connected byupper and lower series of stay bolts 6 and 7.

Arranged exteriorly of the boiler and preferably located in the cab (notshown) is a source 8 of electricity. This electrical generator may be ofany improved type but is herein shown to consist of a battery. Arrangedat the opposite end portions of the water chamber of the boiler andlocated on either side and adjacent to the top thereof are what willsubsequently be termed sta tionary contacts a and I). These contacts areinsulated from the metal of the boiler and are connected with the source8 in a manner to be presently described. Fig. 3 shows the means forsecuring and insulating the contact members from the boiler. In thisconnection it will be observed that a transverse opening 9 is formed inthe side wall of the water chamber,the said opening 9 is interiorlyscrew threaded and receives an exteriorly screw threaded bushing 10. Thebushing 10 is preferably of brass and corresponds in lengthapproximately to the thickness of the side wall. The contact membercomprises a cylindrical body portion 11 considerably greater in lengththan the thickness of the side wall and terminates at its inner end inan enlarged circular portion 12 which corresponds in diameter to thediameter of the bushing or approximately so. The circular portion 12 hasan axial extension 13, the terminal portion of which is non-cylindricalin contour and provided with a platinum contact point 15. Arrangedbetween the circular portion 12 and the inner surface of the side wallis a mica washer 16, and arranged in the bushing 10 is mica packing 17which surrounds the body 11. Arranged at the opposite ends of thepacking 17 and located at the opposite ends of the bushing is steampacking 18 and 19 of non-conductive material. The body 11 is screwthreaded for a portion of its length, as shown at 20, the screw threadedportion being located outwardly from the portion of the body located inthe bushing. A clamping nut 21 is screwed onto the threaded portion 20and arranged between the inner face of the nut and outer face of thecrown sheet is a mica washer 22.

Secured by studs 22 on the inner surface of the boiler and below theinner end portion of the contact member shown in Figs. 2 and 3, is abracket comprising a vertical portion 23, the upper end of whichterminates in a lateral extension 2st, the outer end portion of which isscrew threaded, as shown at 25. \Vhat will subsequently be termed thecircuit closer comprises a tubular body portion 26 and a hollowspherical float 27. The float 27 is provided with a small inlet opening28. An interiorly threaded socket 29 is secured to the outer surface ofthe float and surrounds the opening 28. One end portion of the arm. 26is exteriorly screw threaded, as shown at 30 and is screwed into thesocket 29. The contact member is shown to include a hub portion 31having oppositely extending arms 32 and 33 the former of which isprovided with a platinum contact 33 to bear on the contact 15. The arm33 is exteriorly screw threaded and connection between the upper end ofthe arm 26 and arm 33 is established by means of an internally screwthreaded sleeve 3st, the opposite ends of which engage with the threads35 at the upper end of the arm 26 and the threads of the arm As shown inFigs. 2 and 3, a small space exists between the contiguous ends of thearms 33 and 26 and formed in the sleeve 3% and in alinement with thesaid space is an opening 36. The hub portion 31 is provided in its borewith a bushing 37 which loosely receives the extension 24 of thebracket. A nut 38 is screwed on to the threaded end portion 25 of theextension 24 and prevents lateral displacement of the hub, the nut 38being locked against turning movement by a jam nut 39.

By reference to Fig. 2 it will be seen thatthe stationary contact memberis located above the upper series 6 of the stay bolts and the pivotalsupport or extension 2t is likewise located above the upper series 6.The arm 26 extends downwardly and between two adjacent stay bolts of theupper series, and the lower end portion of the said arm is offset andout of vertical alinement with the pivotal support or extension 24: ofthe bracket.

The circuit from the source 8 extends by the conductor 40 to the outerend portion of the stationary contact member b located on the rear endportion of the boiler, as shown at 40 in Fig. 3. A conductor 4-1 isgrounded, as shown at 42, on the exterior of the boiler and adjacent tothe stationary contact member I). An electrically operated audiblesignal is herein shown to comprise a well known form of bell 42. Oneterminal of the coil in the bell is connected with the opposite terminalof the source by a conductor 43. The opposite terminal of the coil ofthe bell is grounded on the exterior of the boiler adjacent to thecontact a by means of a conductor 4:4. The conductor 41 is connected tothe conductor 44 and a similar connection is established between thestationary contact member a and the conductor 10, by means of theconductor L5.

hen the contacts at the rear end portion of the boiler bear one upon theother, the cir cuit will be through the conductor 40, contact members 13and 32, the boiler conductors 41 and 44, the bell 4L2 and conductor i3.\Vhen the contacts at the forward end portion of the water space of theboiler are in engagement, circuit will be with the conductors 40 and 45,contact member a, circuit closer, boiler, conductor 44, bell 42 andconductor a3.

lVith this construction it will be seen that when the engine is goingdown grade and the surface of the water with respect to the crown sheetis higher at the forward end thereof than at the rear if the water atthe rear end is sufiiciently low to endanger the crown sheet at the rearend, the circuit closer at the rear end portion of the boiler will closethe circuit and the alarm will sound. So also will the circuit closer atthe forward end portion of the water chamber close the circuit when theengine is going up hill. It is well known that most boilers explodewhile the engine is going up grade, because there is practically nothingemployed at present to indicate to the operator the height of the watercolumn at the forward end of the boiler, in fact at this time theconditions are very deceptive for the reason that the depth of the waterat the rear end portion of the boiler is greater than at the forward endportion, whereby the water in the gage glass shows what would beconsidered a safe margin if the engine were on the horizontal.

In most locomotives and traction engines the average steam pressurecarried while the engine is working would collapse the float 27 were notsome means provided for equalizing the pressure on the outer and innersurfaces of the said float. For this reason I have employed the tubulararm 26 and also the inlet openings 28 and 36, whereby the steam from theboiler will pass through the opening 36, arm 26, opening 28 and into thefloat 27. Owing to the shape of the arm when the latter rises, themedial portion thereof will engage one of the bolts in the upper series6 in time to prevent the float from engaging with one of the said stay1biolts and thus avoid injury or denting the oat.

It will be further observed if through negligence the water be permittedto flow into the boiler so as to substantially fill the same, thecircuit will be closed when the surface of the water reaches thecontacts before described.

Although I have shown and described the device as applied to alocomotive or traction boiler, it must be understood however that I amnot to be limited to this specific application since it can be readilyseen that the device will operate equally as well with other types ofboilers or in fact with any supply reservoir or vessel.

Having described my invention What I claim and desire to secure byLetters- Patent is,

1. In a device of the class described, the combination with a steamboiler, an electric circuit and an electrically operated signalconnected in said circuit, of a contact member forming one terminal ofsaid circuit and extending through one wall of the boiler and insulatedtherefrom, a buoyant circuit closer forming the opposite terminal ofsaid circuit and including a tubular arm connected at one end to ahollow float and provided at its opposite end portion with a contact,said circuitcloser being pivotally supported on the interior of theboiler and provided with an inlet opening for establishing communicationbetween the interior of said boiler and float.

2. In a device of the class described, the combination with a tractionboiler provided with a fire-box section, an electric circuit and anelectrically operated signal connected in said circuit; of contactmembers connected in said circuit and arranged at the opposite endportions of said fire-box sec tion, and pivotally mounted circuitclosers arranged in said boiler and connected in said circuit, saidcircuit closers being movable to close the circuit by the liquid fallingbelow a certan point in the boiler.

In testimony whereof I afiix my signature in presence of two witnesses.

CHARLES EVARD ROBISON.

Witnesses:

GRACE RoBIsoN, G. L. CULLMERRY.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

Washington, D. G.

